Scientists have created bacteria covered in tiny semiconductors that generate a potential fuel source from sunlight, carbon dioxide and water. The so-called "cyborg" bugs produce acetic acid, a chemical that can then be turned into fuel and plastic. In lab experiments, the bacteria proved much more efficient at harvesting sunlight than plants. The work was presented at the American Chemical Society meeting in Washington. Researchers have been attempting to artificially replicate photosynthesis for many years.

Solar panel bugs
In nature, the green pigment chlorophyll is key to this process, helping plants to convert carbon dioxide and water, using sunlight, into oxygen and glucose. But despite the fact that it works, scientists say the process is relatively inefficient. This has also been a big problem with most of the artificial systems developed to date. This new approach seeks to improve that efficiency by essentially aiming to equip bacteria with solar panels. After combing through old microbiology literature, researchers realised that some bugs have a natural defence to cadmium, mercury or lead that lets them turn the heavy metal into a sulphide which the bacteria express as a tiny, crystal semiconductor on their surfaces. "It's shamefully simple, we've harnessed a natural ability of these bacteria that had never been looked at through this lens," said Dr Kelsey Sakimoto from Harvard University in Massachusetts, US. "We grow them and we introduce a small amount of cadmium, and naturally they produce cadmium sulphide crystals which then agglomerate on the outsides of their bodies."